if (grep $_ <= 0, @{$angles->[0]}{('A' .. 'C')}) {
    my $zero_angle = 'A';
       if ($angles->[0]{C} <= 0) { $zero_angle = 'C' }
    elsif ($angles->[0]{B} <= 0) { $zero_angle = 'B' }

    my @sides = ('A' .. 'C');
    @sides = grep $_ ne $zero_angle, @sides;

    $sum = 0;
    $sum += $_ for @{$angles->[0]}{@sides};
    $other = 180 - $sum;
    $angles{$var} = $other;
    $angles->[0]{$zero_angle} = 
        sprintf( "%.10f", Math::NumberCruncher::deg2rad( $other ) );
}